Fluorescent light fixture



Oct. 27, 1964 E. F. zuRAwsKl 3,154,001

FLuoREscENT LIGHT FIXTURE Filed sept. 22, 1960 pwma Qjur @gmmwzwowfw fwww@ gw United States 3,154,9@i Patented Oct. 27, 1964 free 3,154,001FLURESCENT LIGHT FIXTURE Edward F. Zurawslri, Chicago, Ill., assigner toGarcy Corporation, a corporation of Iliinois Fiied Sept. 22, 1960, Ser.No. 57,762 2 Claims. (Cl. SiS-40) This invention relates to afluorescent light fixture, and is particularly concerned with means forproviding a warm air return for an air conditioned room havingfluorescent light fixtures recessed in the ceiling.

It is customary to provide fiuorescent light fixtures, particularly whensaid fixtures are recessed in the ceiling, with bottom panels. Althoughbottom panels may be secured to the fixture in any suitable manner, theyare preferably hinged to the lower edge portion of the treffer along oneside thereof, and are latched to the lower edge portion of the troiierat the opposite side thereof. In such installations, the longitudinaledges of the bottom panel abut the inner surface of the longitudinaledges of the troffer. The ends of the bottom panel generally abut thelower edge portion of an end plate secured to each end of the treffer.

In accordance with the present invention, the lower longitudinal edgeportions of the trolfer are flared outwardly to increase the width ofthe lower edge portion of the trofier approximately half an inch. Thewidth of the bottom panel is not changed, and the hinges are so mountedon one side wall of the trofier and the longitudinal side of the bottompanel as to space each longitudinal edge of the frame approximately 1Aof an inch from the lower edge portion of the adjacent side wall of thetrofier.

The length of the bottom panel is approximately half an inch less thanthe longitudinal distance between the end plates. The bottom panel is solocated longitudinally relative to the hinges that each end of thebottom panel is spaced approximately 1A of an inch from the verticalplane of the major body portion of the end plate mounted on the adjacentend of the troffer. If the bottom panel is not hinged to the troffer, itwill be spaced inwardly from the lower edges thereof to provide the samespacing between the perimeter of the bottom panel and the lower edgeportions of the troffer and end plates. An intermediate portion of eachend plate extends inwardly slightly more than 1A of an inch, thendownwardly and outwardly in engagement with the upper edge portion ofthe end of the frame of the bottom panel. The intermediate portion ofthe end plate is lfiared outwardly and downwardly from its engagementwith the upper edge portion f the frame of the bottom panel to engagethe edge of a ceiling panel, or the corresponding edge of an adjacentend plate if two light fixtures are mounted in end to end relationship.Preferably the lowermost edge portion of the end plate is coplanar withthe bottom of the ceiling panel and lowermost surface of the bottompanel.

The outwardly iiared portions of the lower edge portions of the trofferand end plates are provided with elongated slots. The slots on each sideof the fixture are located in a Vertical plane between the outer edgesof the bottom panel and the adjacent edges of the ceiling panel.Similarly, the slots in the end plates are each located in a verticalplane between the end of the bottom panel and the outer surface of theend plate. The slots provide a passageway for the warm air flowingupwardly in an air conditioned room. The location of the slots insuresaccess to the slots by the warm air. The warm air is exhausted from thespace above the ceiling in any suitable manner, as, for example, bymeans of a fan.

The positioning of the slots constituting the warm air return outwardlyof the perimeter of the bottom panel makes the slots substantiallyinconspicious because none of the light can shine directly through anyof the slots. None of the slots can interfere with the normaldistribution of the light from the iiuorescent tubes mounted in thefixture. One advantage inherent in the inconspicuous appearance of theslots is that the slots do not detract from the appearance of theceiling installation. If fixtures constructed in accordance with theinvention are used in rooms that are not air conditioned, and thereforedo not require a warm air return, the fixtures have the same appearanceas similar fixtures not provided with slots. This advantage simplifiesinventory problems for the manufacturer and for the dealers selling thefixtures.

Since the warm air return is independent of the bottom panel, thepresence or absence of a bottom panel does not affect the utilization ofthe slots as a means for exhausting warm air from an air conditionedroom. If it is desired to have fluorescent light fixtures with an openbottom, the same troffers may be used without a bottom panel. It is alsopossible to use troffers having slots for a warm air return with anytype of bottom panels that may be secured to the troffers, or to theceiling adjacent the trofiers, provided only that the air in the roomhas access to the slots.

The structure by means of which the above-mentioned and other advantagesof the invention are attained will be fully described in the followingspecification, taken in conjunction with the accompanying drawingsshowing a preferred illustrative embodiment of the invention, in which:

FIGURE 1 is a perspective view of a light fixture embodying theinvention;

FIG. 2 is an enlarged cross sectional view, taken along the line 2-2 ofFIG. 1, and showing fragmentary portions of ceiling panels adjacent thelongitudinal edges of the fixture;

FIG. 3 is an enlarged fragmentary longitudinal sectional view, takenalong the line 3-3 of FIG. l, showing one end of the light fixture and aportion of an adjacentceiling panel;

FIG. 4 is a fragmentary detail perspective view of the hinge forsecuring one edge of the bottom frame panel A to the troffer;

FIG. 5 is a fragmentary detail perspective view of the slotted sectionof the far siade of the trotter, as viewed in FIG. l, adapted to receivethe hinge shown in FIG. 4; and

FIG. 6 is a cross sectional View, taken along the line 6 6 of FIG. 1.

Referring to the drawings, the troffer 2 comprises a flat top wall 3 andlongitudinally extending side walls 4. Each side wall has a verticalupper section 5, an outwardly curved intermediate section 6, and anoutwardly and downwardly flared lower edge portion 7. The flared portion7 is connected to the curved section 6 by a narrow horizontal portion 8.A plurality of elongated slots 9 extend through the iiared portion 7 inlongitudinally spaced relationship. The number of slots 9 depends uponthe length of the fixture. It is possible to provide a single slot ofany desired length, but a plurality of short slots -is preferred becauseof the more attractive appearance of the fixture provided with slots ofuniform length around the entire perimeter.

The lower edge portion of the troifer extends horizontally outwardly`from the lowermost edge of its fiared portion 7, then upwardly, andloutward-ly, as indicated at 10, 11 and 12 respectively. The section 10is coplanar with the bottom surface of a ceiling panel 13 and bridgesthe gap between the lowermost edge of the flared portion 7 of thetroffer and the adjacent edge of a ceiling panel 13. The section 11abuts the inner edge of the ceiling panel 13. The section 12 extendsinto a kerf 14 in the ceiling panel that helps support the fixture.

The upper portion of the trotter serves as a wiring channel and as ahousing for conventional structure such as a ballast 15, a transversesupport strip 16 at each end of the troffer for supporting socket bases17, and fluorescent light tubes 18 mounted in sockets 19 that areintegral with the socket bases and depend therefrom below the supportstrips 16.

A curved panel 20 extending the length of the trofer has its outer edges21 Welded to the vertical wall sections 5. The portions 22 of the paneladjacent the outer edges 21 are curved above the fluorescent light tubes13 and downwardly to a limited extent between them to form reflectingsurfaces adapted to direct the light downwardly through a bottom panel23. The bottom panel may be formed of glass, plastic, or any othersuitable material.

The bottom panel 23 is supported by a bottom panel frame 24 in the formof a hollow rectangular member having tubular sides 25, 26, and tubularends 27. The outer edge of the tubular side 25, is spaced approximately1A of an inch inwardly from the vertical section 11 of the treffer. Inthis position, the top surface of the tubular side 25 is juxtaposedagainst the underside of the horizontal portion 8 of the troffer. Thetop surface of the tubular side 26 is similarly juxtaposed against theunderside of the horizontal portion 8 on the opposite side of thetroffer. Both outer longitudinal edges of the bottom panel frame 24 arepositioned between the slots 9 in the opposite longitudinal edges of thetroffer. The space between the outer edge of each side 25, 26 and theadjacent depending portion of the lower edge portion 7 of the trolferpermits the warm air rising in an air conditioned room to haveunobstructed access to the longitudinally extending slots 9 at each sideof the fixture.

An end plate 28 is secured to each end of the troffer 2. These endplates are identical, and therefore only one will be described. The endplate comprises a fiat section 29, shaped to conform to the crosssectional configuration of the troler 2, and a flange 30 extendinglaterally from its upper edge and from each side, The flange 30 litssnugly against the end of the troffer to hold the end plate firmly inplace.

As shown in FIGS. l and 3, an intermediate portion of the flat section29 is bent inwardly, as indicated at 31, in a plane above the top 32 ofthe tubular end 27 of the bottom panel frame 24. The intermediateportion of the end plate is bent downwardly, as indicated at 33, toengage the top 32 of the tubular end 27, and then is flared outwardlyand downwardly, as indicated at 34, into the plane of the underside ofthe ceiling panel 13. The outer end of the intermediate portion of theend plate extends upwardly, as indicated at 35, in the plane of the flatsection 29. The upwardly extending portion 35 is juxtaposed against theinner edge of an adjacent ceiling panel 13.

The upstanding portion 35 of the end plate is spaced approximately 1A ofan inch from the outer edge of the tubular end 27 of the bottom panelframe 24. A slot 36, similar to the slots 9, extends toward theoutwardly flared portion 34 of the end plate. The slots 36 cooperatewith the slots 9 to provide a substantially continuous warm air returnextending around the perimeter of the lower edge of the fixture. Theintermediate portions of the ends of the fixture are bent inwardly,because an outward flare, similar to the flare of the lower edgeportions 7 at the sides of the fixture, is impractical. The fixtures aresometimes installed in end to end relationship, and an outward flare atthe end of each fixture would prevent spacing the fixtures in close endto end contact.' In rooms having light fixtures arranged in end to endrelationship, the novel configuration of the end plate provides theadvantages of a slot for the exhaust of warm air from the room withoutinterfering with the end to end relationship of the light fixtures.

Each end of the bottom panel frame 24 is spaced approximately 1A of aninch from the upstanding portion 35 of the end plate. The space betweenthe outer edge of 2, the tubular end 27 of the frame and the verticalportion of the flared section 34 of the troer is unobstructed to allowthe warm air free access to the slot 36. The slot 36 is spaced below thehorizontal section 31 so that the air flowing upwardly through the slot36 can readily pass into the space above the ceiling panel 13.

The warm air return is not affected by the bottom panel, since all ofthe slots 9 and 36 extend through portions of the treffer spacedoutwardly of the bottom panel. Accordingly, the bottom panel 23 may beomitted, or may be replaced by any bottom panel that does not obstructthe slots.

The bottom panel frame 24 may be secured to the lower edge portion ofthe troffer in any suitable manner. One means for securing said bottompanel frame in position comprises one or more hinges 37 secured to oneedge of said bottom panel frame. The opposite edge of said bottom panelframe is secured to the treffer by one or more latches (not shown).

The hinge 37 comprises a transverse section 38 having an upstandingvertical section 39 at one edge and a depending vertical section 4d atits other edge. An elongated horizontal bar 41 extends laterally fromthe lower edge of section 4t). The bar 41 may be integral with thehinge, or may be welded to section 40. The upstanding vertical section39 is inserted through a slot 42 in the outer wall of the tubular side25 of the bottom panel frame 24 and is welded to the inner surface ofsaid tubular side.

The outwardly and downwardly tiared lower edge portion 7 of the troffer2 is provided with a T-shaped slot having a horizontal portion 43slightly longer than the length of the bar 41 and a vertical portion 44depending from the lower edge of the horizontal portion to the loweredge of the treffer. The vertical portion 44 of the slot is preferablydisposed centrally of the horizontal section 43. The vertical portion 44is slightly wider than the transverse section 38 of the hinge, but isnarrower than the length of the bar 41.

The bottom panel frame 24 is attached to the troffer by inserting thebars 41 through the horizontal portions 43 of the T-shaped slots andthen dropping the bottom panel frame in place with the transversesection 38 of each hinge engaged with the vertical portion 44 of theslot. The weight of the bottom frame panel is suicient to hold it inplace. The horizontal bar 41 rests on the bottom section 10 of thetrotter, and the depending vertical section 40 of the hinge spaces thebottom panel frame vertically so that its lower surface is flush withthe bottom of the troffer and with the underside of the ceiling panels13. The transverse section 38 of the hinge spaces the adjacent edge ofthe bottom frame panel approximately 1A of an inch inwardly from thevertical section of the lower edge portion 7 of the troffer.

Although I have described a preferred embodiment of the invention inconsiderable detail, it will be understood that the description thereofis intended to be illustrative, rather that restrictive, as many detailsof construction may be modified or changed without departing from thespirit or scope of the invention. Accordingly, I do not desire tobe'restricted to the exact structure described.

I claim:

l. A light fixture comprising a top, a pair of longitudinally extendingside walls depending from said top, an end plate secured to each end ofsaid top and side walls, said side walls each having a lower edgeportion flared outwardly and downwardly, the edges of said end platesbeing shaped to conform to the shape of the flared portion of said sidewall, each of Said end plates having a lower edge portion extendinginwardly toward the opposite end plate and then downwardly andoutwardly, and a bottom panel frame positioned between the lower edgeportions of said side walls and end plates, said bottom panel framebeing spaced from each of said lower edge portions, each of said loweredge poriOIlS having Slots providing an unobstructed air passagewayextending along each side and each end of said xture, said airpassageway being spaced outwardly of the adjacent edge of said bottompanel frame and inwardly of the outer periphery of said fixture.

2. A light xture comprising a top, a pair of longitudinally extendingside walls depending from said top, each of Said side walls having alower edge portion flared outwardly and downwardly, a hinge having oneportion pivotally connected to the ared lower edge portion of one ofSaid side walls, a bottom panel frame positioned between said lower edgeportions of said side walls, said hinge having a second portion rigidlysecured to said bottorn panel frame and a transverse portion spacingsaid panel from the flared portion of said one side wall, said one sidewall having an air passageway extending therethrough in an unobstructedarea aligned vertically with the space created by the transverse sectionof said hinge between said one side wall and said panel frame, and anend plate abutting corresponding ends of said top and side walls, saidend plate comprising a at plate having 6 an intermediate portion thereofextending inwardly above the upper surface of said panel and downwardlyinto engagement with said panel frame, said intermediate portion havinga lower edge portion extending outwardly and downwardly into thevertical plane of said liat plate, said lower edge portion of said endplate having an unobstructed air passageway extending therethroughoutside the adjacent end of said bottom panel frame.

References Cited in the le of this patent UNITED STATES PATENTS2,312,561 Leonard Mar. 2, 1943 2,321,099 Naysmith June 8, 1943 2,332,770Abernathy Oct. 26, 1943 2,852,663 Stufter et al. Sept, 16, 19582,912,568 Winkler Nov. 10, 1959 2,926,237 Sorenson Feb. 23, 19602,960,602 Kurth et al Nov. 15, 1960 2,991,708 Falk et al. July 1l, 19613,012,133 Archer Dec. 5, 1961

1. A LIGHT FIXTURE COMPRISING A TOP, A PAIR OF LONGITUDINALLY EXTENDINGSIDE WALLS DEPENDING FROM SAID TOP, AN END PLATE SECURED TO EACH END OFSAID TOP AND SIDE WALLS, SAID SIDE WALLS EACH HAVING A LOWER EDGEPORTION FLARED OUTWARDLY AND DOWNWARDLY, THE EDGES OF SAID END PLATESBEING SHAPED TO CONFORM TO THE SHAPE OF THE FLARED PORTION OF SAID SIDEWALL, EACH OF SAID END PLATES HAVING A LOWER EDGE PORTION EXTENDINGINWARDLY TOWARD THE OPPOSITE END PLATE AND THEN DOWNWARDLY ANDOUTWARDLY, AND A BOTTOM PANEL FRAME POSITIONED BETWEEN THE LOWER EDGEPORTIONS OF SAID SIDE WALLS AND END PLATES, SAID BOTTOM PANEL FRAMEBEING SPACED FROM EACH OF SAID LOWER EDGE PORTIONS, EACH OF SAID LOWEREDGE PORTIONS HAVING SLOTS PROVIDING AN UNOBSTRUCTED AIR PASSAGEWAYEXTENDING ALONG EACH SIDE AND EACH END OF SAID FIXTURE, SAID AIRPASSAGEWAY BEING SPACED OUTWARDLY OF THE ADJACENT EDGE OF SAID BOTTOMPANEL FRAME AND INWARDLY OF THE OUTER PERIPHERY OF SAID FIXTURE.